Work-supporting member for printing machines



F. M. ALLEN WORK SUPPORTING MEMBER FOR PRINTING MACHINES Original FiledSept. 10, 1927 May 20, 1930.

- ATTORNEY X Q x INVENTOR ALL N Fatented May 20, 1930 UNITED STATESPATENT OFFICE FRANK M. ALLEN, or SUMMIT, NEW JERSEY, ASSIGNOR 'roGoNGoLEUM-NAIRN, Inc, A CORPORATION on NEWHYORK' WORK-SUPPORTING MEMBERFOR IPRIN'IING MACHINES Beflled for abandoned application Serial No.218,636, filed September 10, 1927. This'applieation filed March 21,1930. Serial No. 437,647.

This invention relates to printing machines, and more particularly toprinting machines of the bed-and-platen type as de scribed and claimedin the Waldron Patent No. 1,145,821.

Printing machines of the type referred to, comprise, in general, a setofplatens carrying printing blocks, which are adapted to be reciprocatedby suitable mechanism to impress a design upon a base material as it isconveyed step by step through the machine over the bed andwork-supporting members. In the present-day machines, thework-supporting members consist of fiat pads each having a wood backingand a top of wool felt of uniform thickness, covered with oilcloth orsimilar material. The pads are suitably cradled in the framework of theprint machine beneath the set of platens, the felt faces being adaptedto provide flat, compressible work-supporting surfaces, against whichthe print blocks may abut without injury to their printing surfaces.Intermediate the worksupporting members orpads, and in a planetherewith, are wood or steel plates, forming with said pads a continuousflat bed over which the work is conveyed. As thefiat print block isbrought into association with the work supported by the flat felt padfor the purpose of depositing paint thereon, or for flattening ormashing the paint previously deposited, a strong cohesive relation isset up between the print block and the work, whereby the raising of theprint block from the printed surface is opposed with great resistance.This efi'ect is particularly noticeable when a relatively heavy layerofpaint is being deposited, as, for example, when decorating hard-surfacedfloor coverings with a film of paint of suflicient thickness to form awearing surface. In consequence, the work is slightly raised 1 from thework-supporting member by the suction of the block, until the opposingforces break the bond and the work is suddenly torn from the block.Frequently this results in spattering the paint and in many'instancesthe paint is raised in pits and points so that the work has an unevenand rough appearance. With relatively slow reciprocation of the platensand blocks, this defect, while apparent, is not serious, but as thespeed of operation is increased, the defect becomes most serious andfunctions as one of the chief factors in limiting the printing capacityof the machine. v The chief object of my invention is to provide a novelwork-supporting member for print machines of the bed-an'd-platen type,which is of simple and durable construction and which is adapted tosubstantially eliminate the defect outlined above and to permit anincreased speed of operation.

In the accompanying drawings, forming a part of this'specification:

Figure 1 illustrates a portion of a conventional bed-an'd-platen printmachine, embodying the novel work-supporting members con-,

structed in accordance with the principles of my invention;

Figure 2 is a longitudinal elevation of said work-supporting members;

Figure 3 is an enlarged sectional elevatio taken on the line33 of Figure2;

Figure 4 is a sectional elevation of a modified form of, work-supportingmember likewise embodying the principles of my invention.

Referring to the drawings: 7

1 designates the platens of a bed-and-platen type print machine,carrying the flat print blocks 2. Beneath'the platens and forming acontinuous surface over which the work to be printed is conveyed step bystep through the machine, is the bed 3 supported by the framework 4. Thebed consists of pads or work-supporting members 5 positioned beneatheach platen and intermediate members or plates 6 of metal or wood.Preferably, the pads or work-supporting members 5 are removably cradledin the frame 4, whereby they may be easily replaced in case of wear ordamage.

According to the principles of my invention, the pad or work-supportingmember 5 is of resilient construction having a worksupporting surfacewhich is-normally conures 2 and 3, I have shown a preferred form ofconstruction of work-supporting member or pad. Such pad comprises abacking mem- "ber 10 of laminated wood slightly greater in surface areathan'the. surface area of its cor-g responding print block. Along eachupper longitudinal edge of the member 10 and attachedthereto are'groovedmetal strips 11 7 adapted to support and retainwa normally convexedspring steel plate 12. The relation of the plate'12 totheretainingmembers 11 is such as to permit free flexing movements of the former,while preventing any substantial lateral movementthereof. Over the plate12 is a thick layer of felt 13 adapted to provide a relatively softsurface against which the print block may abut without injuryto theprinting surface thereof. Preferably, the felt is covered with a goodgrade of oilcloth 13 providing a surface of low friction, over which thework may pass.

a print block, should, in all events, be comparable with the normaldownward pressure exerted by the blocks and platens during the printingoperation. ,I have found it most desirable that the force requiredshould be considerably less than such printing pressure,

- in order to insure a complete flexing of 'the pad to conform with thesurface of the print block. Preferably, the plate 12 is so tempered asto exert a substantially uniform upward pressure over its entire surfacewhen flexed to a flat work-supporting surface, so

is obtained. Y

that a uniform impression of the print block In Figure 4, I have'shown amodifiedform usual manner.

of resilient convex work-supporting member,

consisting of a sponge rubberblock 15', suitably cradled in thesupporting member 16. The sponge rubber block is preferably moulded insuch double convex form as to exert a uniform'upward pressure when theworksupporting surface is compressed by the print block to theplanethereof. Other suitable compressible elastic material may besubstituted for the sponge rubber if desired.

In the operation of a bed-and-platen type printingmachine embodying myinvention, the platens and blocks are reciprocated in the 'upon the worksupported by the convex resilient pad, there is line-contact engagementof such block and work at the center y of the pad in contrast with theoverall plane- As the print block descends contact engagement as in thepresent-day machines. As the print block is forced into furtherengagement by extended line-contact under the pressure exerted by theplaten, the Work-supporting member is flexed to conform with the surfaceof the flat block, thereby causing a complete and uniform contact of theprint block with the work. As the 7' print block, having reachedthe end"of its" downward stroke, commences its upward movement, the work stillfirmly held between the block and. the center of the resilient pad,

is separatedfrom the blockat the edges 0;

smoothly and easily by the line-contact disengagement, as shown inFigure 1. The pad continulngto flex toits normal convex position as'tlieblock'recedes,the;line-contact disengagement of the work and print blockcontinues until the two are entirely separated."

This feature of line-contact disengagement, similar to-the peeling.action in rotary printing machines, entirely avoids the suddenplane-cleavage of the bond between the print block and the work.Furthermore, such operationsubstantially eliminates all spatteringoccurring from the sudden separation of the print block and work, andavoids the formation of pits and points of paint.. Of chief importance,however, is the fact thatby employing work-supporting members having 3the characteristics of myinvention, Iamable to obtaina considerablyincreased speed of reciprocation of the printblocks,'which results inincreased capacity of the print machine, and at the same time producesprints which have a uniformand even finish.

It will be obvious to those skilled in' the art that numerousmodifications may bemade in the manner of carrying out my invention,

and I do not wish to limit its scope, except as defined in the appendedclaims. .1. :J I

This application isa rerfile of application,

Serial No. 218,636, filed September 10th,

* 1. In a bed=and-platenf combination, a printing member having a flatprinting surface and. arresilient work-supporting member, including anormally convexed spring plate, adaptedto be flexed to a substantiallyflat work supporting surface during the printing operatio combination, aflat'block printingmembe'r and a resilient work-supportingmember, saidwork-supporting member having a normally convexed work-supportingsurface adapted to be flexed to a substantially flat work-supportingsurface during the printing opera tion.

3. In a bed-and-platen print machine, in combination, a flat blockprinting member and a resilient work-supporting member, saidwork-supporting member being adapted to cause line-contact engagementanddisen i p i V print machine, in

2. In a bed and-platen:print machine, inf I gagement of the printingmember and the Work.

4. In a bed and platen print machine, in combination, a resilientnormally convex Work supporting member, adapted to flex under printingpressure to provide a .flat Work supporting surfaoe, and a printingmember having a flat printing surface and adapted to reciprocate towardand from the Work supporting member, and to flex the latter into theplane of the former.

5. In a bed-and-platen print machine, in

combination, a printing member having a flat printing surface, and aresilient work supporting member adapted to provide a flatWork-supporting surface during a portion of the print period and tocause line contact disengagement of the printing member and the Work. 7

In testimony whereof, I aflix my signature. FRANK M. ALLEN.

